A gauge hanger is a device that can be positioned in a wellbore to support operational or analysis instruments. A gauge hanger is typically lowered to a desired depth inside tubing in a drilled wellbore on a wireline or workstring. The gauge hanger is set in place by driving grippers radially outwardly with respect to the main axis of the wellbore so that a firm grip is established with the tubing.
One use of a gauge hanger is to support an acoustic gauge system, such as the AD250 produced by Acoustic Data Limited. The AD250 is an acoustic telemetry device that is designed to measure wellbore pressure in real-time. The measurement can then be converted into encoded acoustic wave data and sent to surface as a vibration inside the steel wall of the wellbore tubing. These acoustic waves can be detected by an accelerometer that is bolted to a wellhead. In this way, a device such as the AD250 can provide real-time data about wellbore pressure during production.
A number of techniques exist for setting the gauge hanger in place at a desired depth in the wellbore. These techniques typically involve explosive chemical reactions, or hydraulic/electro-hydraulic processes to provide a driving force. These actuation methods provide a high setting force, which is necessary to fix the gauge hanger securely since there can be high pressures, temperatures and vibrations in the wellbore. Additionally, these techniques provide reliable actuation, which is important when the setting process occurs at a significant depth in an inhospitable wellbore.
An electromechanical actuation device for a gauge hanger is described in WO 2009/085732. In this document a power rod is provided for longitudinal movement along a wellbore. The longitudinal movement of the power rod causes a radial movement of slips which can engage the tubing in the wellbore to set the actuator in place. The electromechanical actuator can then be released and lifted out of the wellbore.